400 V8. To be auctioned in January. http://www.hemmings.com/classifieds/carsforsale/chevrolet/chevelle/1705717.html
Here it is on eBay. http://www.ebay.com/itm/CLASSIC-ORI...OW-SOLID-/281583595514?_trksid=p2054897.l4275 $16,995.00.
From the ebay description: While we are unable to say definitively that the engine is numbers matching, we can say that this 400 cubic inch V8 is at least period correct, and very well could be the original powerplant. The small block sends power to what is believed to be the original automatic transmission. I would have expected a big-time dealer like this to be able to determine the originality of the above items. Very nice car. A power seat and power windows would definitely have added to the comfort level. However, I guess I could learn to live without them.